Sun Ju Ahn joined the KLPGA tour in 2006.
She had a pretty good rookie year, collecting a win and 8
other top tens, including two second place finishes. Despite
that, she was thoroughly overshadowed by another rookie at
the time, Ji Yai Shin.

But in 2007, her career really took off. She
played very well in two Australian events, scoring top tens
in both and even leading the ANZ Masters for a while before
fading to 4th. When she returned to the KLPGA, she made an
immediate impact, winning the second event she played that
year, the first KB Star Tour event. But it was her performance
at the year's biggest event, the Korean Women's Open, that
really put her on the map. She held off American star Cristie
Kerr to win the title and take over first place on the money
list.

Eventually, Shin would reassert her dominance
in a major way, but Ahn would win a third KLPGA event in 2007
and collect 12 top tens in total. She finished third on the
money list, and established herself as a budding superstar
in Korean golf.

2008 did not start as strongly for Ahn, and several
other young players played better than she did for the first half
of the season. She did still manage multiple top tens, but rarely
contended. But in the second half of the season, she turned things
around. She decided to play on the LPGA tour in 2009, and played
in the first Qualifying School sectional. She won it, beating players
such as Michelle Wie and Stacy Lewis in the process. Shortly after
returning to Korea, she finished second at the year's second KLPGA
major, then won her first event of 2008 the following week, the
Samsung Finance. She lost in a playoff to Ji Yai Shin at the year's
third major, the 4th KB Star Tour event. She came really close to
winning at the final event she played that season, the St. Four,
an event jointly sponsored by the Ladies European Tour. Ahn led
most of the week, but Hee Kyung Seo made four straight birdies at
the end of the final round to catch and pass Ahn for the title.

Despite that disappointment, it had been another
great season on the KLPGA for Ahn. She amassed 14 top tens and a
solid record on tour. Now it was time for LPGA Qualifying School
and her chance to join her good friends Eun Hee Ji and Ji Yai Shin
in America. She played terribly in the first round, however, and
eventually had to drop out with an injury. So, she would be returning
to Korea for at least one more year.

2009 was another strong season on the KLPGA for
Big Mama. She was very consistent, achieving 12 top tens on the
year. She won twice and finished third on the money list. She was
so consistent that she led the league in scoring average much of
the year, despite not winning as often as So Yeon Ryu or Hee Kyung
Seo (she eventually finished second behind Seo in that stat).

She also had a good year internationally, the highlight
being a 13th place finish at the US Women's Open, her best Major
finish to date.

In 2008, Ahn had tried and failed to qualify for
the LPGA tour (due to injury). In 2009, she entered JLPGA Q-School
instead, successfully earning a tour card for 2010.

It didn't take her long to make a splash on that
tour. In her very first event, she carded a five shot victory over
a field that included LPGA stars Inbee Park and Jiya Shin, who finished
tied for 2nd. Ahn led the money list most of the year, sometimes
by a huge margin, and wound up becoming the first Korean to ever
win the JLPGA money list.

Her most impressive stretch came in the summer,
when she recorded ten straight top five finishes, which included
three wins. One of those wins was a dominating 7 shot blowout over
Shin. In all, she had 4 wins in 2010, 2 seconds, 2 more thirds and
19 total top tens in 27 starts. In every way, it was a phenomenal
rookie campaign.

Ahn came into the 2011 JLPGA season with a target
on her back. To her credit, she continued her high level of play
without hesitation, racking up four more wins, including her first
Major at the Salonpas Cup, to once again lead the JLPGA money list.
She had become the first foreigner to ever accomplish that feat
twice (even more impressive was that fellow Korean Ji Hee Lee was
#2 on the list, the first foreign 1-2 in JLPGA history). Her win
at the Sankyo Ladies Open in October was the 100th win by a Korean
on that tour, and happened at roughly the same time as Na Yeon Choi
achieved the 100th win by an ethnic Korean on the LPGA. She ended
the year ranked #6 in the world, the second highest ranking Korean
(behind Na Yeon Choi).

Ahn also played four times on the LPGA tour in 2011.
She missed the cut at the US Women's Open and Evian Masters, but
notched top 20s at the British Women's Open and the Mizuno Classic.

Ahn had another strong season on the JLPGA in 2013,
although not quite as good as her first two years (weirdly, she
did not play any LPGA events in 2012). Her biggest win came in May,
when she captured the Salonpas Cup for her second career JLPGA Major;
she beat Inbee Park and Morgan Pressel in a playoff. Among her other
highlights: she lost in a playoff to Bo Mee Lee at the Daikin Orchid
Ladies in March; she lost a playoff to Shanshan Feng at the Meiji
Cup in August; she won her 10th JLPGA event at the Nitori Ladies
in August, and followed that up with her third win of the season
at the next event, the Golf5 Ladies.

Ahn's three wins and 101 million yen was extremely
strong, but not enough for her to win her third straight money list
title. She had to settle for fourth. But Mi Jeong Jeon and Bo Mee
Lee were first and second, meaning Koreans captured three of the
top four spots on the JLPGA money list in 2012!

2013 started as a weaker year for Ahn. She did manage
back-to-back wins on the JLPGA in the Fall, however, , and came
close to making it three straight. In the end she finished 4th on
the money list with around 91 million yen earned, the top Korean
during a season where the Japanese players reestablished control
on their tour.

Ahn reasserted herself on the JLPGA tour in 2014.
She once again led the tour's money list for the third time in her
career, winning five events and earning over 153 million yen. With
Jiyai Shin and Bo Mee Lee, Koreans held three of the top four spots
on the money list for the year. Ahn also was the Captain for the
Korea-Japan Team event, which Korea again won in a rout.

Ahn's most notable result off the Japanese tour
came at the British Women's Open. She was (seemingly) leading the
event after the third round, but then it was noticed she had illegally
created a stance for herself in the bunker on the final hole. This
cost her two strokes and dropped her behind LPGA star Inbee Park.
Ahn struggled in the final round, shooting a 79 to wind up tied
for 9th. A disappointment, but it was still her first top ten at
a Major.

Ahn had another strong year on the JLPGA in 2015.
She finished fourth on the money list and managed two wins with
17 top tens, including two runner-up finishes and six other top
fives. She earned 105 million yen for the year.

Her first win of the year came at the Century 21
Ladies Golf Tournament in July, but her most significant win was
her second, at the Toto Japan Classic. This is the annual event
that is co-sanctioned by the LPGA, and her win there earned her
an LPGA card, which she refused. It was her first career LPGA victory.

Ahn did well in her title defense at the Toto in
2016; indeed, she almost repeated as champion, winding up tied for
third. She also tied for 46th at the US Women's Open and tied for
30th at the HSBC Champions earlier in the season.

On the JLPGA, Sun Ju had another strong year. She
wound up 9th on the money list, notching two wins during the year
and achieving five other top fives and four additional top tens.
She won about 71 million yen in total.

There was talk that Ahn planned to retire at the
end of the 2016 season to start a family, but this has not yet been
confirmed.